KIO::UDSEntry, switch to a single std::vector for more performance.
This new implementation is the fastest in the [[ https://phabricator.kde.org/D12659 | autotests ]].
The replace in KFileItem::setName is due to the new assert in insert() renaming a file.
The replace in ListJobPrivate::slotListEntries are due to the new assert in insert() running Kfind.